The heating trays allow restaurants to keep french fries, fried onions, hash browns and other fried or non-fried food products hot and crisp longer before being served to customers.
The typical frying process includes the quick heating of food in a deep fryer at around and above 350 degrees F. During this frying process all moisture is quickly removed from the surface of the fried product giving it a hot and crisp appearance.
However, food items, such as french fries, fried onion rings, hash browns and other fried products, deteriorate quickly once removed from their primary cooking source. The typical hold time for french fries and other fried food products is between 5 and 7 minutes. Thereafter, such food products become soft and develop a greasy appearance. In fact, internal food moisture quickly creeps towards the outside of the food and softens the surface leading to many customer complaints about greasy and old french fries. The use of radiant heat and/or convection air in keeping food items hot and crisp has been described in other appliances and patents, such as U.S. Pat. Nos. 4,499,818 and 6,114,659 and 6,261,621 and others.
The original idea of improving holding times of fried food was described in U.S. Pat. No. 4,499,818 from 1985. U.S. Pat. No. 6,261,621 describes a fried food holding unit that is comprised of an upper heater (overhead heat lamps) and a lower heater and forced hot air through and across the fried food and with recirculating hot air. Many tests have shown that overhead heating lamps in any application will cause fried food to become moist quickly. U.S. Pat. No. 6,114,659 describes a food product bin having a bottom portion with a surface for receiving food products to be warmed, said bottom portion having first and second opposed edges and third and fourth opposed edges, first and second end walls disposed at said first and second opposite edges of said bottom portion, the regions above said bottom portion and along said third and fourth opposite edges between said first and second walls being substantially open to ambient atmosphere.